000
FXUS04 KWBC 150632
QPFPFD

QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
231 AM EDT WED MAY 15 2013


PRELIM DAY 1 QPF DISCUSSION
VALID MAY 15/1200 UTC THRU MAY 16/1200 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR


DAY 1

EASTERN PORTIONS OF THE SOUTHERN PLAINS

THERE CONTINUES TO BE LOW CONFIDENCE WITH THE EVOLUTION OF
CONVECTION AHEAD OF THE UPPER TROF THAT HAS MOVED OUT OF NORTHERN
MEXICO AND INTO THE SOUTHERN PLAINS.  THE NAM CONEST AGAIN IS
SHOWING THE HEAVIEST SOLUTION WITH A LARGE QPF MAX--AREAL AVERAGE
3-5"--OVER NORTH CENTRAL TO NORTHEAST TX.  THE REMAINDER OF THE
GUIDANCE IS CONSIDERABLY LIGHTER---DEPICTING A BROAD AREA OF
MODERATE TO ISOLATED HEAVY TOTALS ACROSS EASTERN TX--INTO EASTERN
OK---WESTERN AR WITH AREAL AVG AMOUNTS OF .25- 1"+.  THERE ARE A
LOT OF DETAIL DIFFERENCES ON THE SHORTER TIME SCALES WITH QPF IN
THE AXIS OF ABOVE AVERAGE PW VALUES THAT WILL BE TO THE EAST OF
THE UPPER TROF AXIS.  WHILE CONFIDENCE IS LOW WITH DETAILS---IT IS
HIGHER FOR POTENTIAL FOR MODERATE TO ISOLATED HEAVY TOTALS ACROSS
THESE AREAS.  DAY 1 QPF LEANED TOWARD THE DETAILS OF THE HI RES
ARW AND THE ECMWF.

EASTERN GREAT LAKES---NY STATE INTO NEW ENGLAND

NORTHERN STREAM HEIGHT FALLS MOVING QUICKLY EASTWARD FROM THE
UPPER LAKES INTO NEW ENGLAND DAY 1 WILL PUSH THE ASSOCIATED
OCCLUDED AND WARM FRONTAL BOUNDARIES EASTWARD THROUGH THE
NORTHEAST.  ISENTROPIC LIFT AHEAD OF THESE BOUNDARIES WILL SUPPORT
LIGHT TO MODERATE PRECIPITATION AMOUNTS FROM THE EASTERN GREAT
LAKES---THROUGH NY STATE AND INTO MOST OF NEW ENGLAND.  THE
HEAVIEST AMOUNTS LIKELY ACROSS FAR NORTHERN NY INTO NORTHERN NEW
ENGLAND AND TO THE NORTH OF THE U.S./CANADIAN BORDER ACROSS FAR
EASTERN ONTARIO AND INTO QB WHERE LARGE SCALE UVVS WILL BE
STRONGEST---WITH MAX .25-.50" AREAL AVERAGE AMOUNTS.  LIGHTER
AMOUNTS EXPECTED FOR AREAS FARTHER TO THE SOUTH.

OH VALLEY INTO THE MID MS VALLEY

THE WESTERN PORTION OF THE FRONTAL BOUNDARY MOVING THROUGH THE
NORTHEAST DAY 1 WILL BE MUCH SLOWER MOVING AS IT PRESSES SOUTHWARD
INTO THE MID MS VALLEY AND TOWARD THE OH VALLEY REGION AS IT
BECOMES MORE PARALLEL TO THE MID LEVEL WESTERLY FLOW ALOFT.  ABOVE
AVERAGE PW VALUES IN AN UNSTABLE AIRMASS ALONG AND AHEAD OF THIS
FRONT WILL SUPPORT CONVECTIVE POTENTIAL FROM THE MID MS VALLEY
INTO THE OH VALLEY REGION.  SLOW MOVEMENT OR TRAINING OF CELLS IN
A WEST TO EAST DIRECTION POSSIBLE ALONG THIS BOUNDARY WEDNESDAY
NIGHT INTO EARLY THURSDAY MORNING---SUPPORTING POTENTIAL FOR
ISOLATED HEAVY TOTALS.  LOW CONFIDENCE ON QPF DETAILS HAS KEPT
AREAL AVERAGE AMOUNTS IN THE .10-.25"+ RANGE.

CENTRAL ROCKIES INTO THE CENTRAL HIGH PLAINS

WIDESPREAD SCATTERED CONVECTION LIKELY AGAIN FROM THE CENTRAL
ROCKIES EASTWARD INTO THE CENTRAL HIGH PLAINS IN A BROADLY UPPER
DIFFLUENT PATTERN AHEAD OF SHORTWAVE ENERGY PUSHING EAST
NORTHEASTWARD FROM THE GREAT BASIN INTO THE CENTRAL
ROCKIES/CENTRAL HIGH PLAINS.  LOW CONFIDENCE ON QPF DETAILS ACROSS
THESE AREAS HAS LEAD TO THE DEPICTION OF LIGHT TO LOCALLY MODERATE
AREAL AVERAGE AMOUNTS.

PACIFIC NORTHWEST INTO NORTHERN CA

SEVERAL PIECES OF SHORTWAVE ENERGY FORECAST TO MOVE EASTWARD OFF
THE NORTHEAST PACIFIC AND INTO THE PACIFIC NORTHWEST/NORTHERN CA
DAY 1.  WEAK ONSHORE FLOW WILL KEEP AREAL AVERAGE PRECIPITATION
AMOUNT ON THE LIGHT TO LOCALLY MODERATE SIDE ACROSS THE COASTAL
PACIFIC NORTHWEST INTO NORTHERN CA.

ORAVEC

GRAPHICS AVAILABLE ON THE WEB AT WWW.WPC.NCEP.NOAA.GOV

24HR QP VT 16/12Z
 0.01 499674 496665 494657 486640 483634 480631 474623 466616
      459612 456610 452610 442610 439611 434615 425623 420624
      415628 406638 402643 395650 393655 388662 383672 381683
      380688 381692 385700 388703 394705 399705 403706 410706
      415706 419707 416717 412725 404730 398734 392743 391747
      388749 387754 384759 380762 377771 380783 383792 382799
      380805 376808 373818 374825 375832 378845 378854 377864
      374872 366889 362898 360901 357902 355906 349915 344918
      339919 324923 314928 302932 297934 294936 289938 286940
      283944 279947 275954 273961 264975 261982 262985 265989
      273994 279997 284997 288994 293993 299987 309988 318986
      322985 326986 334984 345980 349978 352978 359974 363968
      368961 372958 377960 379962 381969 384973 387976 391979
      397982 403992 404000 401006 400009 398011 395013 390021
      388025 389031 390038 387043 383042 378039 375036 372035
      366033 363033 357037 354046 356050 357057 357063 359066
      363068 366072 371079 372083 374084 380087 383088 386090
      388090 397086 407081 410085 411088 409091 405102 397108
      392109 389111 385116 388120 393118 404118 408119 413121
      421126 424127 427126 433119 438117 443119 446121 452118
      459110 458104 454099 451096 446095 441092 439085 440080
      442078 446081 450072 453069 456069 459065 462061 465059
      468053 470047 471041 470034 467024 461017 450017 444017
      440015 434008 428996 426991 424982 420969 419954 418943
      417934 416920 416906 416901 415893 416866 417845 417831
      420822 423817 427815 433816 442818 447819 453820 464822
      472827 500861 511885 517893 524898 528899 534897 537894
      539888 543876 545869 545865 541842 538834 535821 529804
      523786 520782 517771 514766 512759 505730 503721 502714
      502702 500691 500684 498675 499674
 0.01 518273 517263 514253 506234 496221 493224 492227 494236
      495239 494240 491238 488234 483233 481230 477226 474229
      472226 478218 482218 485214 485207 489206 490202 488200
      483200 478205 471208 467208 463210 449213 434219 430220
      429224 428231 426235 417233 415230 413225 416220 419218
      425212 426209 428203 432196 453170 455168 459166 464167
      468170 475174 480182 484184 488184 491182 495181 501175
      505165 506160 506155 501145 497137 494134 492135 485141
      480141 475140 471140 469142 461145 452146 448142 444140
      436140 436144 437149 437155 435160 434164 431167 428170
      425170 421173 419179 418182 416189 414192 413196 408205
      405209 404213 402224 399230 397232 395234 393240 397248
      399251 402251 406251 411253 416254 422254 427251 440247
      445247 449250 454257 461261 471266 476267 481271 487275
      507288 510287 514282 518273
 0.25 486674 484666 480658 472650 465642 456636 449633 439631
      434633 430635 425638 420643 418667 418669 421674 425680
      428684 433688 437688 444698 446703 444708 444715 445722
      446725 445728 442732 432742 428746 427752 429758 432761
      441763 444768 446777 448784 451790 458799 466804 475808
      483812 490819 494822 499824 507829 511832 515830 517827
      519828 522826 520810 514797 509784 506776 503770 500764
      497755 495741 493732 490723 485712 484701 485692 486681
      486674
 0.25 489247 488242 486241 484243 481241 479237 476233 473236
      469240 471246 476251 479253 482254 487251 489247
 0.25 463221 463220 460219 459219 459224 459225 460224 463222
      463221
 0.25 402810 402806 401801 397796 394796 391798 387804 387811
      387817 387833 387848 387862 389893 390908 390917 391927
      394952 395960 399959 401953 402947 403937 403931 402912
      403897 403881 402866 402850 402822 402810
 0.25 364944 362934 359930 356928 350926 347926 339930 336933
      331934 325936 320936 317935 311936 304941 297947 292955
      285968 283979 282984 284986 287985 294980 303977 313975
      325975 336971 341970 347969 353964 359956 363949 364944
 0.50 498785 498780 496776 494772 489766 486763 482762 478761
      475761 474766 478773 481776 484779 487784 491785 495787
      498785
 0.50 498799 497799 494799 493798 491797 488796 487796 488796
      491799 492801 494802 495802 498800 498799
 0.50 447654 445653 444652 440651 437651 434652 434656 437658
      437659 441658 443657 446656 447654
 0.50 356946 354939 352935 348934 340936 332940 327945 323946
      315945 308948 297955 292959 291967 290974 292975 297975
      310970 314968 318970 324970 338965 346963 351958 354953
      356946
 1.00 347947 347944 344944 341945 338945 337946 336948 335950
      334953 336957 337958 340959 343958 345955 347951 347948
      347947

$$